Relationships are everything in the Senate, and Charles E. Schumer, the presumptive top Democrat in the next Congress, has them down pat.

"Most senators have been there a while. ... They do have these strong relationships, and they're deep relationships, because they spend a lot of time together," said former Sen. Ted Kaufman, D-Del. Kaufman spent decades observing the chamber as a top aide for Joseph R. Biden Jr., and served alongside Schumer after being appointed to Biden's Senate seat from 2009 to 2010, after Biden became vice president.

But even in the clubby atmosphere of the Senate, Schumer's network is particularly deep. Of the 43 Democrats, and two independents who caucus with them, who are not named Schumer, roughly a third were recruited directly by the New Yorker when he ran the party's campaign arm. Many of those senators have risen to their own power spots, including the current chairman of the Democratic Senatorial Campaign Committee, Jon Tester of Montana, and two potential presidential candidates, Bernard Sanders of Vermont and ex-Sen. Jim Webb of Virginia.

Oh, and he was home-state colleagues with another presidential candidate, Hillary Rodham Clinton, as well as one of the chamber's brightest stars, Kirsten Gillibrand. He organized the last presidential inauguration as chairman of the Senate Rules and Administration Committee. And he used to live with the No. 2 Senate Democrat, Richard J. Durbin of Illinois.

The guy is wired.

For example, who could get the Senate's liberal champion, Elizabeth Warren of Massachusetts, and the most conservative Democrat, Joe Manchin III of West Virginia, on the same page? Yep. Schumer.

Within hours of retiring Minority Leader Harry Reid's endorsement of Schumer for leader, Manchin sent out a statement that said Schumer "has proven that he can work with moderate and progressive Members of the Democratic Caucus, and importantly, with Republican Members from across the aisle. He also shares my values and priorities in ensuring middle class Americans are able to succeed in our country. I have complete confidence that Chuck Schumer will be a tremendous leader of our party, and he has my full support."

On Monday Warren, a stalwart critic of Wall Street's influence on Congress, provided Schumer cover and praised him for supporting her brainchild, the Consumer Financial Protection Bureau. "I talk about this in my book, that Chuck was one of the first people to support the Consumer Financial Protection Bureau and to get out there and fight for it," she told NPR.

Asked if Schumer was "too close to Wall Street," Warren pushed back.

"Look, I worry about everyone being too close to Wall Street, let's be clear," she said, before circling back to his support for her causes. "Chuck was very much there on the consumer agency setting it up, building it, protecting it, very much there ... on student loans, ... on Social Security ... these are powerful issues and we fought side by side. I think he's going to be terrific on that," she added.

As leaders, Reid and Schumer certainly have different styles. Schumer beams in the spotlight. Reid barely raises his voice above a whisper. The two complement each other, particularly in public. At a news conference in February, Schumer cracked a joke about the Nevadan's reference to a "box canyon," saying the very Western thing was like a "dead end on Ninth Avenue." When no one laughed, Schumer said, "Are you so serious you don't laugh at anything?"

Without missing a beat, Reid heckled from the side, "We only laugh at things that are funny."

"Yeah, yeah, yeah," Schumer said, beaming.

"There's inside and outside. ... [Reid's] not going to go on 'Meet the Press.' He's inside," Kaufman said, adding that the accomplishments of the 111th Congress — the stimulus, the Affordable Care Act, the Dodd-Frank financial regulation law — can be credited to Reid's skills and leadership.

Schumer, though, is as comfortable plotting floor strategy as going national with the messaging. "Schumer is an inside and outside guy," Kaufman said. "He'll go on 'Face the Nation.' ... He is extraordinary among extraordinary people."

Schumer first came to Congress in the 1980 elections, and two of his classmates, Reps. Harold Rogers, R-Ky., and Christopher H. Smith, R-N.J., are still serving in that chamber. In the Senate, three of his colleagues from that 1980 House class are serving: Dan Coats, R-Ind., Pat Roberts, R-Kan., and Ron Wyden, D-Ore.

A native of Brooklyn's Flatbush neighborhood, he shares an alma mater, James Madison High School, with Supreme Court Justice Ruth Bader Ginsburg and ex-Sen. Norm Coleman, R-Minn., head of the American Action Network. He went to Harvard with Sen. Al Franken, D-Minn., a member of the 2008 class Schumer recruited. Sanders also grew up in Flatbush.

His 34-plus years in Congress also have produced a cottage industry of former staffers who have gone into every aspect of public policy in Washington, from Katie Beirne Fallon, who heads President Barack Obama's legislative affairs team, to Eric Hauser, the communications director at the AFL-CIO, to Roger Hollingsworth, executive vice president of the Managed Fund Association. Brian Fallon (Katie's husband) is headed to the nascent Hillary Rodham Clinton presidential campaign to be its top spokesman.

Schumer loves visiting 1600 Pennsylvania Ave. Of the current Senate leadership ranks, he has visited the Obama White House (visiting not just Obama, but seeing staffers and attending events) more than 100 times. Durbin has visited 82 times, Reid 74, Patty Murray of Washington 34 times and Majority Leader Mitch McConnell, R-Ky., 37 times.

Overall, Kaufman boiled Schumer's success down to three top things. "No. 1. He is really, really smart," the former college professor said. "No. 2, he understands politics. If there's something you need ... Schumer has an incredible ability to look at your personal political situation and [policy] ... and figure out where they come together."